Dual Nature Of Light Question 376
Question: A parallel beam of electrons travelling in x-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum p in the y-direction then for a majority of electrons passing through the slit (h is Planck’s constant):
Options:
A) $ |P_{y}|>h $
B) $ |P_{y}|<h $
C) $ |P_{y}|=h $
D) $ |P_{y}|»h, $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] From Bragg’s equation $ d\sin \theta =\lambda \text{ }\sin \theta =\frac{\lambda }{d}<1 $
$ \therefore \lambda <d $ $ \frac{h}{|p_{y}|}<d[ \because \lambda =\frac{h}{|p_{y}|} ] $
$ \therefore h<|p_{y}|d $
BETA
